Oxygen flow regulator



June l2, 1945. STRANGE -v 2,378,047

OXYGEN FLow REGULATOR Filed pct. Y e, 1942 l l INVENTOR.

Wl TNEJJES. B Y WA( menne June 12, 194s UNITED STATES PATENT" ortica OXYGEN FLOW REGULATOR John P. Strange, Wilkinsburg, Pa., asslgnor to Mine Safety Appliances Company, Pittsburgh, Pa., a corporation of Pennsylvania Application october e, 1942, serial No. 60,951

4 claims. (ci. 1st-153) This invention relateslto breathing apparatus,

vand more particularly to a regulator for control` ling the ow of compressed oxygen t the user, such as an aviator iiying at high altitudes.

It is among the objects of this invention to provide an oxygen flow regulator which reduces high pressure oxygen to a usable pressure, which delivers the oxygen only during inhalation and then with a minimum of effort by the user, and which mixes avariable quantity of air with the oxygen,

depending upon the altitude at which the appaor other suitable device to open the pilot valve i and thus release the oxygen pressure from the pressure operated means so that the main valve can open and allow oxygen to be supplied to the user. As soon as he exhales, the pilot valve c losesv and the oxygen pressure on the fluid pressure operated means increases to cause the latter to.

again close the main valve. Thus, the oxygen pressure does the work of opening and closing the main valve.' Before the oxygen reaches the user. it preferably passes through a device in which itV mixes with air that it draws inthrough a passage controlled by an aneroid valve so that at high altitudes less air will be mixed with the oxygen.

The preferredembodiment of this invention is illustrated in the accompanying drawing in which Fig. 1 is a plan view of my now regulator with the diaphragm removed in|order to show the interiorof the device, and Fig. 2 is a side view of the regulator partly broken away to show some of the elements in sectlon.

Referringv to the drawing, a cylindrical housing I is provided at one side with a threaded outlet nipple vz to which the inhalation tube: of breath;

ing apparatus is connected. The other end of thetube is connected to the face piece worn by the referred to herein as an aviator. Mounted in the opposite side o! the housing and extendingrut through it is .a main valve l which is byva 'supply pipe l to a source of oxygen'un'der' high pressure, such las anoxygen bottle or tank (not shown). This valve has a central inlet passagef'l extending from the oxygen supply pipe to a chamber l in the valve.

inlet passage is an outlet passage 9 that is connected to an outlet pipe I0. The other endof this pipe is connected through means described later to the inside of housing I soy that when the valve is open, oxygen flows through it and pipe I0 into the housing and then out through nipple 2 tothe aviator. J i

Ii the valve were always open, oxygen would be delivered during exhalation as well as inhalation, and thus wasted. `Accordingly, it is'a feature of this invention that the valve is closed Aautomatically during exhalation. In order to close the valve, a valve plug I2 is slidably mounted in the wall of the valve chamber opposite to the inner end of its inlet passage. The inner end of this plug carries a rubber insert Il for seating against the end of the passage to thereby shut off the valve. The valve normally is maintained closed by means ofviluidpressure operated means, such as a Bourdon tube Ill that is rigidly mounted at one end near the side of the housing with its interior in communication with a coupling I8 extending .through the housing wall. The outer end of this coupling is connected to a small pipe I1 the opposite end of which is connected to valve I outside of the housing. The valve at that point isv provided with av transverse passage IB (Fig. 1) that connects the pipe with the Yinlet passage 'l of the'valve. The Bourdon tube is thus continuously in communication with the supply ofhigh pressure oxygen which tends'to straighten or expand the tube. The free end oi' the tube is pivotally connected by a short link 20 to one end of a lever 2l the opposite end of which is pivotally connected at 22 to the back wall of the housing. Valve plug I! is biiurcated for receiving the intermediate portion of the lever which has a slot through which extends a pin 23 that pivotally connects thelever to the valve plug. When the Bourdon tube expands, it swings the free end of the lever to the leit to the full line position shown in Fig. i and thus moves the valve plug inwardly v toclosethevalve. y Y f For the purpose of permitting the Bourdon tube to contract'so that the mein valve can open during inhalation, the anchored end of the tube is provided with an outlet that normally is closed by a pilot valve Il. The pilot valve includes a lever 21 that is pivotally mounted on a. post 2l Extending out from this chamber at one side of the projecting fromthe back wall of the housing. A.

spring 2l connected to the lever normally holds close the valve.

the lever carries a roller 30. When the pilot valve is opened, the oxygen in the Bourdon tube escapes faster than einigen can enter the tube through the small pipe I1 from the source of supply, so the tube contracts. This result may be accomplished by using a very small pipe, or by placing in the pipe a restriction 3|, as shown in Fig. 2, provided with an opening that is smaller than the pilot valve opening.

As shown in Fig. l, the outlet pipe l from main valve 4 is connected to an aspirating nozzle 36 in the outer end of a transverse passage Il through a cylindrical casing 38 that is mounted in a recess in the wall of the housing. Thus the casing is located partly inside and partly outside of the housing. The inner end of passage 8l opens into the housing, and its central portion communicates with the hollow interior of the casing which has an air inlet 39 at its exposed outer end, as shown in Fig. 2. This inlet normally is closed by a disc 4i pressed outwardly by a spring 42 carried on a cross bar 43 extending across lthe inside of the casing. Oxygen injected through nozzle 36 creates a great enough suction to overcome the resistance of spring 42 and thus draws air in through the casing and delivers it mixed with the oxygen to the inside of the housing from which it is 'withdrawn through the breathing tube 3 during inhalation. To reduce the amount of air drawn in at higher altitudes, the casing contains an aneroid valve M of conventional form.

In order to operate the pilot valve, the open side of the housingis sealed by a iiexible diaphragm 5| (Fig. 2) mounted in a ring I2 screwed into the housing. The central portion o! the diaphragm carries a rigid disc 53 that engages the roller 30 on the pilot valve lever. When the aviator inhales, the diaphragm is sucked inwardly and it thereby depresses the pilot valve lever and l opens the pilot valve. This occurs even at low altitudes'because spring 42 in casing 38 is strong enough to keep air inlet 39 closed until diaphragm 5I has opened the pilot valve. Opening of the pilot valve releases the oxygen pressure from inside the Bourdon tube which thereupon starts to contract and open the main valve.

Opening of the main valve decreases the pres sure in the restricted pipe il so that theBourdon tube contracts further and permits a greater flow of oxygen through pipe lo into the housing. The pressure of the oxygen in the main valve against valve plug I2 also helps to open that valve. As soon as the wearer exhales, the diaphragm 5| is forced outwardly and the pilot valve is closed by its spring 28. Pressure immediately starts to build up in the' Bourdon tube which begins to expand and thus close the main valve. Closing of the main valve increases the pressure in pipe I1 so that the pressure likewise is increased in the Bourdon tube to completely The torce developed by the Bourdon tube and multiplied by the leverage system by which it is connected to the valve plug I2 is sufilcient to hold the main valve closed until the aviator inhales again.

It will be seen that the small force developed by inhalation acts on a diaphragmto open the pilot valve. The opening in the pilot valve is so small that only a small force is required to control it. Most oi' the work of opening and closing the main valve is done by the pressure of the oxygen itself, so the breathing resistance Y of this nowregulator is very small.

2,878,047 the valve closed as shown. The opposite end oi According to the provisions oi the patent statutes, I have explained the principle and construction of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

l. A `ilow regulator through which oxygen is supplied to the wearer of breathing apparatus. said regulator comprising a main valve adapted to be connected to a source of oxygen under pressure, a Bourdon tube anchored at one end, means operatively connecting the other end of the tube with said valve, a conduit adapted to connect said oxygen under pressure with said tube whereby to expand the tube and thereby normally maintain said valve closed, a normally closed pilot valve associated with said tube, and means adapted to be actuated by the inhalation of said wearer for opening the pilot valve to release the oxygen pressure from said tube 'whereby the tube contracts and the main valve is opened.

2. A flow regulator through which oxygen issupplied to the wearer of breathing apparatus, `said regulator comprising a housing provided with an open side and with an outlet for a gas to be breathed by said wearer, a exible diaphragm closing said open side and adapted to be' drawn inwardly when the wearer inhales through said outlet, a. main .valve carried by the housing and adapted to be connected to a source of oxygen under pressure and having an outlet connected to the inside of .the housing, a Bourdon tube anchored at one end in the housing, lever means operatively connecting the opposite end of the tube to said valve, a conduit connecting the inlet side of the valve vwith said tube whereby to expand the tube and to thereby normally maintain said valve closed, a normally closed pilot valve mounted inthe housing in connication with said tube. and means in the nous operatively connecting said diaphragm with the pilot valve so that when the diaphragm is drawn inwardly it opens the pilot valve and releases the oxygen pressure from said tube whereby the main valve is opened.

3. A ilow regulator through which oxygen is supplied to the wearer of breathing apparatus, said regulator comprising a housing provided with an open side and with an outlet for s. gas

phragm closing said open side and adapted to be drawn inwardly when the wearer inhalesthrough said outlet, a main valve carried by the housing and adapted to be connected to e source of oxygen under pressure and having an outlet connected to the inside of the housing, said valve including a slidable closure member, a Bourdon tube anchored at one end inthe housing, lever means operatively connecting the free end of the tube with said closure member, a restricted con duit connecting the inlet side of the valve with said tube whereby to expand the tube and thereby normally maintain said valve closed, a normally closed pilot valve for said tube mounted in the housing, and means-in the housing operativeiy connecting said diaphragm with the pilot vaive so that when the diaphragm is drawn inwardly it opens the pilot valve and releases the oxygen pressure from said tube whereby the main valve is opened.

4. Ailow regulator through which oxygen is supplied to the wearer of breathing apparatus.

said regulator comprising a main valve adapted to b e connected to a source of oxygen under pressure, a Bourdon 4tube anchored at one end,

' means operatively connecting the other end of the tube with said valve, a conduit adapted to connect lsaid oxygen under pressure with said tube whereby to expand the tube for normally maintaining said valve closed, a pilot valve' connected to said tube, a spring pressed lever nor- JOHN P. STRANGE. 

